Table 1. Three-Point Ultrasound Grading Scale for Fatty Infiltration in the Rotator Cuff Muscles.

Grade	Echogenicity	Architecture
0	Isoechoic to the overlying muscle	Clearly visible intramuscular tendons and identifiable pennate pattern
1	Slightly increased echogenicity compared with the overlying muscle	Partially visible intramuscular tendons and pennate pattern
2	Markedly increased echogenicity compared with the overlying muscle	No discernible intramuscular tendons or pennate pattern

Modified from Strobel et al.¹³⁾